Beef Fat Enriched with Polyunsaturated Fatty Acid Biohydrogenation Products Improves Insulin Sensitivity Without Altering Dyslipidemia in Insulin Resistant JCR:LA-cp Rats.

The main dietary sources of trans fatty acids are partially hydrogenated vegetable oils (PHVO), and products derived from polyunsaturated fatty acid biohydrogenation (PUFA-BHP) in ruminants. Trans fatty acid intake has historically been associated with negative effects on health, generating an anti-trans fat campaign to reduce their consumption. The profiles and effects on health of PHVO and PUFA-BHP can, however, be quite different. Dairy products naturally enriched with vaccenic and rumenic acids have many purported health benefits, but the putative benefits of beef fat naturally enriched with PUFA-BHP have not been investigated. The objective of the present experiment was to determine the effects of beef peri-renal fat (PRF) with differing enrichments of PUFA-BHP on lipid and insulin metabolism in a rodent model of dyslipidemia and insulin resistance (JCR:LA-cp rat). The results showed that 6 weeks of diet supplementation with beef PRF naturally enriched due to flaxseed (FS-PRF) or sunflower-seed (SS-PRF) feeding to cattle significantly improved plasma fasting insulin levels and insulin sensitivity, postprandial insulin levels (only in the FS-PRF) without altering dyslipidemia. Moreover, FS-PRF but not SS-PRF attenuated adipose tissue accumulation. Therefore, enhancing levels of PUFA-BHP in beef PRF with FS feeding may be a useful approach to maximize the health-conferring value of beef-derived fats.